The Harvard-educated lawyer is a first-generation Dominican American with a career in public service. His nomination could face a GOP backlash over his Justice Department activities.

WASHINGTON — President Obama intends to tap the nation's top civil rights enforcer as the new secretary of Labor, a choice seen Sunday as an opportunity to raise the department's profile as the White House tackles immigration reform.

The expected nomination of Thomas E. Perez, the assistant attorney general for the Justice Department's Civil Rights Division, would make him the only Latino in the Cabinet at this point in Obama's second term.

Two Cabinet-level Latinos from Obama's first term decided not to stay on. Hilda L. Solis, a former California congresswoman, resigned as Labor secretary, and Ken Salazar, a former Colorado senator, is leaving the post of Interior secretary.

A Harvard-educated lawyer, Perez is a first-generation Dominican American with a career in public service. His nomination would be welcomed by Democrats and members of organized labor, who see him as a tireless advocate of worker and civil rights.

The nomination, which requires Senate confirmation, could face a backlash from Republicans over Justice Department activities. Notably, Perez has filed civil rights lawsuits against law enforcement officials — including one last year against Sheriff Joe Arpaio, the brash Maricopa County, Ariz., lawman. The suit accuses Arpaio's department of a "pattern of unconstitutional conduct" against Latinos in the state, which has led the nation in clamping down on illegal immigrants.

An announcement of Perez's nomination is expected but is not imminent, sources familiar with the deliberations confirmed Sunday.

The Labor Department post could play an important role in the president's second term, as Obama has made immigration reform a priority. One of the thorniest issues is the creation of a temporary worker program that Republicans want but that the president has not explicitly proposed.

Because of his background and the policy implications for the workplace and employment, analysts say, Perez could become a leading voice on the issue.

"He's a first-generation American, so in a way his story is the immigrant story," said Christine Owens, executive director of the National Employment Law Project, an advocacy group for workers. "He's always been deeply committed to immigrant workers' rights, and I do think he can bring both a professional and personal perspective as we implement immigration reform."

Frank Sharry, executive director of the immigrant rights group America's Voice, said Perez could become a champion for immigration overhaul. "He's the guy who's going to fight like hell," Sharry said. "He's not combative, but he's determined."

More broadly, Perez's main challenge may be to increase the visibility and influence of the Labor Department, which has diminished over the years even as technology and competitive global forces have put severe pressures on American workers.

U.S. unemployment remains a stubborn problem, even though the nation's jobless rate dropped to a four-year low of 7.7% last month. About 40% of the unemployed have been without work for more than six months, raising serious concerns that millions of American workers could fall into a permanent state of joblessness.

In recent years, the Labor secretary didn't have a seat on the White House National Economic Council, and more often it was the Education Department that took the lead on initiatives such as employee training and workplace innovation, said Harry Holzer, a Georgetown University professor and former Labor Department chief economist in the Clinton administration.

"That's the challenge of the new secretary, to try to raise the profile of the department, to get the department back at the center of these discussions," Holzer said.

Officials from organized labor have long been impressed by Perez. "The AFL-CIO believes Perez would bring the skills and passion working people need to an important agency," said Jeff Hauser, a spokesman.

Perez, appointed as assistant attorney general at the Civil Rights Division in 2009, has spent his career in public service at the federal, state and local levels, according to a department biography.

The former secretary for Maryland's Department of Labor, Licensing and Regulation, Perez also was the first Latino to be elected to the Montgomery County Council and, in 2005, to serve as its president.

A graduate of Harvard Law School and Harvard's John F. Kennedy School of Government, Perez was a Justice Department attorney for 12 years prosecuting civil rights cases and was a deputy assistant attorney general in the Clinton administration.

Perez also worked during the Clinton administration as director of the Office of Civil Rights at the Health and Human Services Department. He was previously on the staff of the late Sen. Edward M. Kennedy (D-Mass.).

The confirmation of some of Obama's second-term nominees has taken a rocky course. Republicans in the Senate protested the choice of Chuck Hagel, the former Republican senator from Nebraska, as Defense secretary and staged a nearly 13-hour filibuster on the nomination of John Brennan as CIA director.

"He'll be a controversial nominee," one Democratic strategist familiar with the Senate said of Perez. The strategist asked not to be identified to speak frankly about expected GOP objections.